Start off with the dog to your left, so when he sits his shoulder should be equal to your hips and facing straight ahead. Take the end of the lead in your right hand and the slack from the dog in your left. Keep just enough leash in your left hand so that when you give a tug, the dog feels it immediately and there is not excess slack. Now simply take one or two small steps, stop and tell your dog to " heel" as you tug on his leash. Now tell your dog to sit. Reward him and continue again. One small step now becomes 2, them 3 etc and when you stop you want the dog to stop beside you and facing front. If he stops and sits facing you, correct him, and reward him again. The trick here is small steps, the heel command, then sit with a correction and a reward. It may take some time but practicie this with your dog, 3-4 times a day for only about 5 min each time. You will soon be walking with your dog by your side and when you stop he will also stop and sit facing front. Please let me emphasize again, start slow with small steps and only do this for about 5 min or so. Four times a day for 5 min each time is better than twice a day for 10 min. When it stops being fun or you get frustrated because he' s not doing as well as you want...it' s time for a break. Repetition + reward = results. Good Luck.